This namespace is used to group special pages, reports and interfaces that are generated "on demand" by MediaWiki and that are not directly editable. It is not possible to create pages in this namespace except by modifying or extending the MediaWiki software.

The namespace that has no prefix separated by a colon. Commonly called the "main namespace" or "mainspace". This namespace typically contains the bulk of the content pages in a wiki. This namespace generally has no special properties.

This page, and subpages of it, can be used by users to record information about themselves or to test and draft new content. Pages of the form "User:UserName/Foo.js" or "User:UserName/Foo.css" can only be edited by the user themselves or by administrators.

To create an internal link to the file page, you need to add a colon to the front of the namespace: [[:File:Wiki.png|right]] produces File:Wiki.png. The standard MediaWiki installation has alias "Image" for File namespace - See Namespace aliases.

The Category namespace contains categories, dynamic lists of other pages. To facilitate this, linking directly to a category page does not output an inline link, but instead includes the page into the associated category page. So the code [[Category:Help]] causes a category link to appear at the bottom of the page (at the bottom in the box marked "Category"). Clicking on that link takes you to the category page, where this page is visible in the category list.

To create an inline link to a category page, you need to add a colon to the front of the namespace: [[:Category:Help]] produces Category:Help. See Help:Categories for more details on category link syntax.

Namespace names can be translated into languages other than English and individual namespaces can be renamed, as set by a wiki's system admins. These names are known as the 'localized' namespace names. However, all namespaces have a 'canonical name', the original English name which will work on any installation of MediaWiki. So linking to User:Foo will always locate the user page for the user foo, whether the wiki is in French (where the localized name would be Utilisateur:Foo), Russian (Участник:Foo), or Hindi (सदस्य:Foo).

The canonical namespace names are given in the table to the right along with their localized names on this wiki.

On some wikis there are also namespace aliases: alternative names that will also be resolved to the localised names. For instance, a wiki might define "T" as an alias for Template, such that typing T:Foo is equivalent to Template:Foo, saving a few characters and seconds. An actual example would be on the English Wikipedia, where "WP" is an alias for Project, which is the namespace "Wikipedia".

By default, "Image" is an alias for File, so [[Image:Wiki.png]] is equivalent to [[File:Wiki.png]].

There are a number of ways by which the namespace of a particular page can be identified:

Magic words

The magic word{{NAMESPACE}} returns the value of the namespace the page is in.

JavaScript

The JavaScript variable wgCanonicalNamespace contains the full namespace name. The variable wgNamespaceNumber contains the numerical index of the namespace.

CSS

The <body> tag of the HTML page output is given two CSS classes that vary by namespace: A class ns-#, where # is the index of the namespace, and ns-XXX, where XXX is "subject" for all subject namespaces, "special" for pages in the Special namespace, and "talk" for talk namespaces. So CSS code such as the following can be used to change the appearance of an object based on its namespace:

.ns-subjecta{/* Almost all links on subject pages to be green. */color:#00FF00;}.ns-talka{/* Links on talk pages to be blue. */color:#0000FF;}.ns-3a{/* and links on user talk pages to be red */color:#FF0000;}

API

You can get a complete list of all the namespaces used on this wiki and some settings for each from the MediaWiki API: